JP2019163247A - Dental adhesive composition including chain transfer agent - Google Patents

Abstract

The present invention provides mechanical properties and aesthetics required for restorative materials, and has excellent durability adhesion to teeth, and is resistant to the effects of polymerization shrinkage stress even when filled and cured at once. Providing a 1-paste dental adhesive composition that develops its properties. (A) an acidic group-free polymerizable monomer, (b) an acidic group-containing polymerizable monomer, (c) a filler, (d) a photopolymerization initiator, (e) a chain transfer agent, A dental adhesive composition comprising a chain transfer agent containing an α-alkylstyrene compound. [Selection figure] None

Description

  The present invention relates to a dental adhesive used in the dental field, a dental self-adhesive composite resin, a dental self-adhesive abutment building material, a dental resin cement, a dental self-adhesive surface coating material, and a dental self-adhesive The present invention relates to a dental adhesive composition such as an adhesive pit / fissure sealant and a dental self-adhesive nail polish.

In dental clinics, a dental filling composite resin is used for aesthetic and functional recovery of tooth defects caused by caries or fractures. In general, a composite resin for dental filling is prepared by mixing a resin matrix composed of several kinds of polymerizable monomers, various fillers such as inorganic fillers and organic-inorganic composite fillers, and a polymerization initiator to form a uniform paste. .
Requirements for dental composite resin include high mechanical strength that can withstand occlusal pressure, color tone and light transmission similar to natural teeth, low polymerization shrinkage that suppresses the formation of a contraction gap during polymerization and curing, and polishing Surface smoothness and gloss maintenance, high X-ray contrast to facilitate prognosis, sustained release of various ions such as fluorine that strengthens the tooth and suppresses secondary caries, and dentists perform filling operations The operability at the time is excellent.

  Among composite resins, a composite resin called a bulk fill type that has a high photocuring depth and reduced polymerization shrinkage has appeared. Compared to conventional composite resins, the photocuring depth is high, and it is possible to fill and harden a large deep cavity without laminating and filling it. This shortens the time required for filling operation and light irradiation. It is possible to reduce the burden on the treatment of the operator and the patient. However, by filling and curing all at once, the volume polymerization shrinkage generated during polymerization and the polymerization shrinkage stress applied to the fossa wall are significantly increased compared to the case of laminating filling and curing, and the contraction gap during polymerization is increased. Concerns about the formation and secondary caries caused by it remained. In particular, when the composite resin is cured using a high-power light irradiator that has become widespread recently, the polymerization progresses rapidly, so the polymerization shrinkage stress of the composite resin tends to increase in proportion to the light irradiation intensity. was there.

Recently, a one-paste self-adhesive composite resin has appeared. Since this self-adhesive composite resin has adhesion to enamel and dentin alone, it does not require an adhesion operation with a bonding material unlike conventional composite resins, and can be easily repaired. In addition, since the self-adhesive composite resin can be repaired simply by filling and curing the cavity, a technical error during adhesive repair by the operator, that is, insufficient air drying during the bonding operation by the bonding material, It is possible to eliminate the influence of the coating layer thickness control and the like, and it can be expected that a more reliable and error-free repair is possible.
However, the acidic group-containing polymerizable monomer contained in the resin component in order to develop the tooth adhesiveness of the self-adhesive composite resin must be in a certain amount in the composition in order to ensure sufficient adhesive strength. It was necessary to mix. In other words, when the filling amount of the inorganic filler is increased in order to improve the mechanical properties of the self-adhesive composite resin, the adhesiveness tends to decrease, and these have a trade-off relationship. Therefore, in order to ensure adhesiveness, it is necessary to ensure a certain amount of resin content, resulting in an increase in polymerization shrinkage due to polymerization and curing of the resin component, and at the bonding interface with the tooth structure. There has been a problem in that the adhesive force is reduced due to the occurrence of polymerization shrinkage stress in the direction of pulling off the film. For this reason, the self-adhesive composite resin is currently required to have long-term stable durable adhesion.

  Furthermore, in the self-adhesive bulk-fill type composite resin that combines a single paste type self-adhesive composite resin with high photocuring depth, in addition to the occurrence of polymerization shrinkage stress accompanying a certain amount of resin content as described above, Since the polymerization shrinkage stress is increased by photocuring with, it has been extremely difficult to obtain a long-term stable adhesive strength to the tooth.

  Patent Document 1 reports a technique of blending a photocleavable polymerizable monomer in order to reduce polymerization shrinkage stress of a composite resin. These photocleavable polymerizable monomers are capable of reducing volume polymerization shrinkage and polymerization shrinkage stress by cleaving a part of a crosslinked network of a polymer formed by polymerization. However, when the blending amount of the photocleavable polymerizable monomer is excessively increased, there is a problem that the viscosity is increased or the mechanical properties are decreased.

  Patent Document 2 also reports a technique of adding a polymerizable stable radical in order to reduce the polymerization shrinkage stress of the composite resin. These radical chain transfer agents are said to be able to reduce polymerization shrinkage stress by delaying the gel point during polymerization. However, according to the results of the study by the present inventors, the effect of reducing polymerization shrinkage stress due to the incorporation of polymerizable stable radicals is poor, and when the amount is increased, the photocuring depth tends to decrease significantly. confirmed.

  Patent Document 3 proposes a technique of blending an α-alkylstyrene compound with a high-speed photopolymerization initiator composition in which an α-diketone compound, an amine compound, and a photoacid generator are combined. When a polymerizable composition containing the photopolymerization initiator of the high-speed polymerization system is filled in the cavity, a rapid polymerization shrinkage stress accompanying the high-speed polymerization reaction acts on the interface between the polymer cured body and the cavity and a contraction gap is likely to occur. . In this document, by blending an α-alkylstyrene compound with the photopolymerization initiator of the high-speed polymerization system, a polymerized cured product having excellent cavity wall compatibility and mechanical strength, in which polymerization shrinkage stress is suppressed. It is reported that it can be obtained. However, this document expresses the effect by combining an α-alkylstyrene compound with a high-speed polymerization system, and α is compared with a conventional photopolymerization initiator system composed of an α-diketone compound and an amine compound. -It is stated that when an alkylstyrene compound is blended, sufficient mechanical strength and cavity wall compatibility cannot be obtained. In addition, the adhesiveness to the tooth is not taken into consideration, and the effect on them is unknown.

  As described above, it has mechanical properties and aesthetics such as hardness, bending strength, compressive strength, etc. required for filling and restoration materials, and is hardly affected by polymerization shrinkage stress, and has a durable adhesive strength to tooth. There was no excellent one-paste dental adhesive restorative material. Furthermore, when these restoration materials are filled and photocured in a lump, the durable adhesive strength is not clinically sufficient, and technical problems remain.

Special table 2009-539861 Special table 2016-532640 gazette JP 2016-169180 A

  The object of the present invention is to provide a dental adhesive used in the dental field, a dental self-adhesive composite resin, a dental self-adhesive abutment building material, a dental resin cement, a dental self-adhesive surface coating, and a dental It is a dental adhesive composition used in the dental field such as a self-adhesive pit and fissure sealant, a dental self-adhesive nail polish material, etc. for living hard tissues (dental enamel and dentin) A dental adhesive restorative material with durable adhesive that can be stably bonded for a long period of time, high mechanical properties that can withstand occlusal pressure, and excellent color compatibility that can be used for aesthetic restoration It is to provide. Furthermore, the dental adhesive restorative material of the present invention has a good durable adhesive that can be used without causing clinical problems such as detachment even when the deep and large cavities are collectively filled and cured. It also has the characteristics.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have solved the above-mentioned problems by including an α-alkylstyrene compound as a radical chain transfer agent in a photo-curable repair material having self-adhesiveness. Has been found to be possible, leading to the present invention. In other words, by including an α-alkylstyrene compound as a chain transfer agent, it becomes possible to reduce polymerization shrinkage stress while maintaining high curability, and mechanical properties as a restoration material and durable adhesion to a tooth are provided. It becomes possible to provide a self-adhesive repair material that does not deteriorate. Furthermore, the restoration material of the present invention makes the refractive index before curing of the polymerizable component relatively close to the refractive index of the filler, thereby increasing the transparency before curing, and filling and curing all large deep cavities at once. It is also possible to provide a deep photocuring depth that can be done. Even when the restoration material of the present invention is a bulk fill type that is easily affected by such a polymerization shrinkage stress, it exhibits a long-term durable adhesive property to a tooth.

  The mechanism by which the dental adhesive composition of the present invention exhibits such excellent effects is not clear, but is presumed to be due to the following reason. Generally, a radical chain transfer agent once receives a radical from a polymer chain grown by radical polymerization and stops the growth of the polymer. Thereafter, the monomer is attacked again to form monomer radicals, and the polymerization is started again. That is, the function of delaying the formation of a polymer network (gelation point) during polymerization is exhibited by temporarily stopping the polymer growth in this way. However, due to such properties, if the amount of the chain transfer agent added is increased, the function of stopping the polymer growth becomes stronger, so that it tends to function as a polymerization inhibitor, leading to a decrease in the polymerization rate. However, among the radical chain transfer agents, it has been clarified that the α-alkylstyrene compound not only has an excellent gel point delay effect, but also has excellent properties such as not causing a decrease in the polymerization rate. Furthermore, the α-alkylstyrene compound has a great advantage that it maintains these characteristics even after being stored at room temperature for a long period of time, and is excellent in storage stability as compared with other chain transfer agents. Due to the notable advantages of such α-alkylstyrene compounds, it is considered that the dental adhesive composition of the present invention has a significantly reduced polymerization shrinkage stress and exhibits high mechanical properties and excellent durable adhesiveness. It is done.

That is, the present inventors provide the following invention in this application.
(A) an acidic group-free polymerizable monomer,
(B) an acidic group-containing polymerizable monomer,
(C) filler,
(D) a photopolymerization initiator,
(E) a chain transfer agent,
A dental adhesive composition comprising
(E) The dental adhesive composition, wherein the chain transfer agent comprises an α-alkylstyrene compound.

  The present invention relates to a one-paste type dental adhesive composition having mechanical properties and aesthetics required for a restoration material, and having excellent durable adhesive strength to tooth. Furthermore, the composition of the present invention is hardly affected by polymerization shrinkage stress even when it is filled and cured in a lump, and exhibits good durability adhesion.

Hereinafter, each component in the dental adhesive composition containing the chain transfer agent of the present invention will be described in detail.
<(A) Acidic group-free polymerizable monomer>
The (a) non-acidic group-containing polymerizable monomer that can be used in the present invention is a known monofunctional and / or polyfunctional polymerizable monomer having no acidic group that is generally used in the dental field. It can be used without any restriction from the mass. Typical examples that are generally used suitably are (meth) acrylate monomers or (meth) acryloyl polymerizable monomers having an acryloyl group and / or a methacryloyl group. In the present invention, both the acryloyl group-containing polymerizable monomer and the methacryloyl group-containing polymerizable monomer are comprehensively described as (meth) acrylate or (meth) acryloyl.

A specific example of the (meth) acrylate polymerizable monomer that can be used as the (a) acidic group-free polymerizable monomer is as follows.
Monofunctional monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate (n-butyl (meth) acrylate, i-butyl (meth) acrylate), hexyl (meth) acrylate, Dicyclopentenyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, allyl (Meth) acrylates such as (meth) acrylate, 2-ethoxyethyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, glycerol (meth) acrylate, and isobornyl (meth) acrylate Silane compounds such as tellurium, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, 2- (N, N-dimethylamino) ethyl (meth) acrylate, N- Examples thereof include nitrogen-containing compounds such as methylol (meth) acrylamide and diacetone (meth) acrylamide.

  As the aromatic bifunctional monomer, 2,2-bis (4- (meth) acryloyloxyphenyl) propane, 2,2-bis (4- (3- (meth) acryloyloxy-2-hydroxypropoxy) ) Phenyl) propane, 2,2-bis (4- (meth) acryloyloxyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxydiethoxyphenyl) propane, 2,2-bis (4- (Meth) acryloyloxytetraethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxypentaethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxydipropoxyphenyl) propane, 2, (4- (Meth) acryloyloxyethoxyphenyl) -2 (4- (meth) acryloyloxydieto Cyphenyl) propane, 2 (4- (meth) acryloyloxydiethoxyphenyl) -2 (4- (meth) acryloyloxytriethoxyphenyl) propane, 2 (4- (meth) acryloyloxydipropoxyphenyl) -2 (4 -(Meth) acryloyloxytriethoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxydipropoxyphenyl) propane, 2,2-bis (4- (meth) acryloyloxyisopropoxyphenyl) propane, etc. Is mentioned.

  Examples of the aliphatic bifunctional monomer include 2-hydroxy-3-acryloyloxypropyl methacrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, Triethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butanediol di ( Examples include meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and glycerol di (meth) acrylate.

  Examples of the trifunctional monomer include trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, trimethylolmethane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and the like.

  Examples of the tetrafunctional monomer include pentaerythritol tetra (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate.

  As the urethane-based polymerizable monomer, a polymerizable monomer having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 3-chloro-2-hydroxypropyl (meth) acrylate And adducts of diisocyanate compounds such as methylcyclohexane diisocyanate, methylenebis (4-cyclohexylisocyanate), hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, diisocyanate methylmethylbenzene, 4,4-diphenylmethane diisocyanate. And di (meth) acrylate having a difunctional or trifunctional or higher urethane bond.

In addition to these (meth) acrylate polymerizable monomers, there is no limitation even if an oligomer or a prepolymer having at least one polymerizable group in the molecule is used. Moreover, there is no problem even if it has a substituent such as a fluoro group in the same molecule.
The polymerizable monomers described above can be used not only alone but also in combination.

<(B) Acidic group-containing polymerizable monomer>
The (b) acidic group-containing polymerizable monomer contained in the dental adhesive composition of the present invention interacts with a living hard tissue (natural tooth enamel or dentin) that becomes an adherend. To develop adhesiveness.
The (b) acidic group-containing polymerizable monomer that can be used in the dental adhesive composition of the present invention can be used without any limitation as long as it is a polymerizable monomer having an acidic group. (B) Specific examples of the acidic group contained in the acidic group-containing polymerizable monomer include a phosphoric acid group, a pyrophosphoric acid group, a phosphonic acid group, a carboxylic acid group, a sulfonic acid group, and a thiophosphoric acid group. However, it is not limited to these. (B) The number of unsaturated groups capable of radical polymerization possessed by the acidic group-containing polymerizable monomer (monofunctional group or polyfunctional group) and the kind thereof can be used without any limitation. (B) Specific examples of the unsaturated group contained in the acidic group-containing polymerizable monomer include acryloyl group, methacryloyl group, styryl group, vinyl group, allyl group, etc. Among these unsaturated groups, acryloyl group And / or an acidic group-containing polymerizable monomer having a methacryloyl group.

  These (b) acidic group-containing polymerizable monomers can also contain other functional groups such as alkyl groups, halogens, amino groups, glycidyl groups and hydroxyl groups in the molecule, and (b) acidic groups. As the group-containing polymerizable monomer, not only a monomer having a short main chain but also an oligomer or prepolymer having a long main chain can be used without any limitation. In addition, (b) a derivative of the acidic group-containing polymerizable monomer, such as a metal salt, ammonium salt or acid chloride partially neutralized with the acidic group of the acidic group-containing polymerizable monomer Any material that does not adversely affect the adhesion to various adherends can be used.

Specific examples of the (b) acidic group-containing polymerizable monomer that can be used in the dental adhesive composition of the present invention are as follows. In the present specification, both the acryloyl group-containing polymerizable monomer and the methacryloyl group-containing polymerizable monomer are comprehensively represented by (meth) acrylate or (meth) acryloyl.
Examples of the acidic group-containing polymerizable monomer having a phosphoric acid group include (meth) acryloyloxymethyl dihydrogen phosphate, 2- (meth) acryloyloxyethyl dihydrogen phosphate, 3- (meth) acryloyloxypropyl dihydro Genphosphate, 4- (meth) acryloyloxybutyl dihydrogen phosphate, 5- (meth) acryloyloxypentyl dihydrogen phosphate, 6- (meth) acryloyloxyhexyl dihydrogen phosphate, 7- (meth) acryloyloxyheptyl Dihydrogen phosphate, 8- (meth) acryloyloxyoctyl dihydrogen phosphate, 9- (meth) acryloyloxynonyl dihydrogen phosphate, 10- (meth) acetate Royloxydecyl dihydrogen phosphate, 11- (meth) acryloyloxyundecyl dihydrogen phosphate, 12- (meth) acryloyl oxide decyl dihydrogen phosphate, 16- (meth) acryloyloxyhexadecyl dihydrogen phosphate, 20 -(Meth) acryloyloxyeicosyl dihydrogen phosphate, di (meth) acryloyloxyethyl hydrogen phosphate, di (meth) acryloyloxybutyl hydrogen phosphate, di (meth) acryloyloxyhexyl hydrogen phosphate, di (meth) Acryloyloxyoctyl hydrogen phosphate, di (meth) acryloyloxynonyl hydrogen phosphate, di (meth) actyl Royloxydecyl hydrogen phosphate, 1,3-di (meth) acryloyloxypropyl-2-dihydrogen phosphate, 2- (meth) acryloyloxyethylphenyl hydrogen phosphate, 2- (meth) acryloyloxyethyl 2′- Examples include, but are not limited to, acidic group-containing polymerizable monomers such as bromoethyl hydrogen phosphate and (meth) acryloyloxyethyl phenylphosphonate.

  Examples of the acidic group-containing polymerizable monomer having a pyrophosphate group include di [2- (meth) acryloyloxyethyl pyrophosphate], di [3- (meth) acryloyloxypropyl) pyrophosphate, di [ 4- (meth) acryloyloxybutyl], di [5- (meth) acryloyloxypentyl] pyrophosphate, di [6- (meth) acryloyloxyhexyl) pyrophosphate, di [7- (meth) acryloyloxyheptyl pyrophosphate ], Di [8- (meth) acryloyloxyoctyl] pyrophosphate, di [9- (meth) acryloyloxynonyl] pyrophosphate, di [10- (meth) acryloyloxydecyl] pyrophosphate, di [12- (Meth) acryloyloxide decyl], tetra [2- (meth) acryloyloxyethyl pyrophosphate ], Although acidic group-containing polymerizable monomer such as tripyrophosphate [2- (meth) acryloyloxyethyl] are exemplified, but the invention is not limited thereto.

  Moreover, as the polymerizable monomer having a carboxylic acid group, (meth) acrylic acid, 2-chloro (meth) acrylic acid, 3-chloro (meth) acrylic acid, 2-cyano (meth) acrylic acid, aconitic acid , Mesaconic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, glutaconic acid, citraconic acid, uraconic acid, 1,4-di (meth) acryloyloxyethyl pyromellitic acid, 6- (meth) Acryloyloxynaphthalene-1,2,6-tricarboxylic acid, 1-butene 1,2,4-tricarboxylic acid, 3-butene 1,2,3-tricarboxylic acid, N- (meth) acryloyl-p-aminobenzoic acid, N- (meth) acryloyl-5-aminosalicylic acid, 4- (meth) acryloyloxyethyl trimellitic acid and its anhydride, 4- (meth) acrylic Royloxybutyl trimellitic acid and its anhydride, 2- (meth) acryloyloxybenzoic acid, β- (meth) acryloyloxyethyl hydrogen succinate, β- (meth) acryloyloxyethyl hydrogen maleate, 11- (meth) acryloyloxy-1,1-undecanedicarboxylic acid, p-vinylbenzoic acid 4- (meth) acryloyloxyethoxycarbonylphthalic acid, 4- (meth) acryloyloxybutyloxycarbonylphthalic acid, 4- (meth ) Acryloyloxyhexyloxycarbonylphthalic acid, 4- (meth) acryloyloxyoctyloxycarbonylphthalic acid, 4- (meth) acryloyloxydecyloxycarbonylphthalic acid and their acid anhydrides, 5- (meth) acryloylaminopenty Carboxylic acid, 6- (meth) acryloyloxy-1,1-hexanedicarboxylic acid, 8- (meth) acryloyloxy-1,1-octanedicarboxylic acid, 10- (meth) acryloyloxy-1,1-decanedicarboxylic acid 11- (meth) acryloyloxy-1,1-undecanedicarboxylic acid-containing polymerizable monomers, and the like, but are not limited thereto.

  Examples of the acidic group-containing polymerizable monomer having a phosphonic acid group include 5- (meth) acryloyloxypentyl-3-phosphonopropionate and 6- (meth) acryloyloxyhexyl-3-phosphonopropiate. Onet, 10- (meth) acryloyloxydecyl-3-phosphonopropionate, (6-methacryloxy) hexylphosphonoacetate, 6- (meth) acryloyloxyhexyl-3-phosphonoacetate, 10- ( Examples include, but are not limited to, acidic group-containing polymerizable monomers such as (meth) acryloyloxydecyl-3-phosphonoacetate.

Examples of the acidic group-containing polymerizable monomer having a sulfonic acid group include 2- (meth) acrylamido-2-methylpropanesulfonic acid, styrenesulfonic acid, 2-sulfoethyl (meth) acrylate, 4- (meta). ) Acid group-containing polymerizable monomers such as acryloyloxybenzene sulfonic acid and 3- (meth) acryloyloxypropane sulfonic acid, but are not limited thereto.
These acidic group-containing polymerizable monomers can be used alone or in combination.

  Among these acidic group-containing polymerizable monomers, 10-methacryloyloxydecyl dihydrogen phosphate, (6-methacryloxy) hexylphosphonoacetate, 6-methacryloyloxyhexyl-3-phosphonoacetate, 4-methacryloyl It is preferable to use oxyethyl trimellitic acid and its anhydride, 4-acryloyloxyethyl trimellitic acid and its anhydride, and the like.

  The (a) acidic group-free polymerizable monomer and (b) acidic group-containing polymerizable monomer that can be used in the dental adhesive composition of the present invention are (a) acidic group-free in weight ratio. Polymerizable monomer: (b) Acidic group-containing polymerizable monomer = Preferably included in a weight ratio of 99: 1 to 70:30, more preferably 95: 5 to 80:20. (B) When the weight ratio of the acidic group-containing polymerizable monomer is less than 1, the effect is not recognized in self-adhesion to living hard tissues (such as enamel and dentin of natural teeth). On the other hand, when the weight ratio of the (b) acidic group-containing polymerizable monomer exceeds 30, problems such as a decrease in mechanical strength due to inhibition of polymerization of other polymerizable monomers occur.

<(F) Acidic group-free hydrophilic polymerizable monomer>
Furthermore, when imparting high self-adhesiveness to the tooth substance to the dental adhesive composition of the present invention, (a) a part of the acidic group-free polymerizable monomer is (f) an acidic group-free hydrophilic group. It is preferable to further contain a polymerizable monomer. (F) Strengthening adhesiveness by improving wettability of living body hard tissue (natural tooth enamel and dentin), etc., which becomes an adherend by including a hydrophilic polymerizable monomer containing no acidic group I can do it.
In this specification, an acidic group-free hydrophilic polymerizable monomer means a polymerizable monomer having a solubility of 10 parts by weight or more in 100 parts by weight of water at 23 ° C. The other polymerizable monomer is defined as a hydrophobic polymerizable monomer. That is, 10 g of a polymerizable monomer is added to 100 g of water kept at 23 ° C. in a sample bottle, and the mixture is stirred for 10 minutes and then left to stand. When the mixture mixed in the sample bottle is observed after 10 minutes, the polymerizable monomer that dissolves uniformly and transparently or semi-transparently is a non-acidic hydrophilic polymerizable monomer that does not dissolve. The monomer was a hydrophobic polymerizable monomer.

  Specific examples of (f) acidic group-free hydrophilic polymerizable monomers that can be used in the dental adhesive composition of the present invention include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl. (Meth) acrylate, 3-hydroxypropyl (meth) acrylate, 1,2-dihydroxypropyl (meth) acrylate, 1,3-dihydroxypropyl (meth) acrylate, 2,3-dihydroxypropyl (meth) acrylate, 2-hydroxy Propyl-1,3-di (meth) acrylate, 3-hydroxypropyl-1,2-di (meth) acrylate, pentaerythritol di (meth) acrylate, 2-trimethylammonium ethyl (meth) acryl chloride, (meth) acrylamide 2-hydroxyethyl (meth) acrylamide Polyethylene glycol di (meth) acrylate (having 9 or more oxyethylene groups), 2-hydroxy-3-acryloyloxypropyl methacrylate, 2-hydroxy-1-dimethacryloyloxypropane, dimethylacrylamide, acryloyl Examples thereof include, but are not limited to, morpholine, isopropylacrylamide, diethylacrylamide, dimethylaminopropylacrylamide, and hydroxyethylacrylamide.

  These (f) acidic group-free hydrophilic polymerizable monomers can be used alone or in combination. Among these (f) acidic group-free hydrophilic polymerizable monomers, those having a solubility in 100 parts by weight of water at 23 ° C. of preferably 20 parts by weight or more are preferable, and more preferably dissolved in 100 parts by weight of water at 23 ° C. The property is 40 parts by weight or more. Specifically, 2-hydroxyethyl (meth) acrylate, polyethylene glycol di (meth) acrylate (having 9 oxyethylene groups), polyethylene glycol di (meth) acrylate (having 14 oxyethylene groups) ), Polyethylene glycol di (meth) acrylate (having 23 oxyethylene groups), 2-hydroxy-3-acryloyloxypropyl methacrylate, 2-hydroxy-1-dimethacryloyloxypropane, dimethyl Examples include acrylamide, acryloylmorpholine, isopropylacrylamide, diethylacrylamide, dimethylaminopropylacrylamide, and hydroxyethylacrylamide.

  The content of the (f) acidic group-free hydrophilic polymerizable monomer that can be used in the dental adhesive composition of the present invention is 5 (a) in 100 parts by weight of the acidic group-free polymerizable monomer. It is preferable to contain by -70 weight part, More preferably, it is 7-60 weight part, More preferably, it is 10-50 weight part. (A) When the content of (f) the hydrophilic polymerizable monomer in the acidic group-free polymerizable monomer exceeds 70 parts by weight, the physical properties are adversely affected because the polymerization of other polymerizable monomers is inhibited. There is a risk of giving. On the other hand, when the content of (f) the hydrophilic polymerization monomer is less than 5 parts by weight, the wettability with respect to the living hard tissue becomes poor.

  In order to give the dental adhesive composition of the present invention adhesion to a noble metal, it is also effective for the present invention to use a polymerizable monomer containing a sulfur atom in the molecule. As long as it is a polymerizable monomer containing a sulfur atom in the molecule, the type and number of unsaturated groups and the presence or absence of other functional groups can be used without any problems.

  Specific examples of the polymerizable monomer containing a sulfur atom that can be used in the dental adhesive composition of the present invention include (meth) acrylate having a triazine thiol group, (meth) acrylate having a mercapto group, (Meth) acrylates having polysulfide groups, (meth) acrylates having thiophosphate groups, (meth) acrylates having disulfide cyclic groups, (meth) acrylates having mercaptodithiazole groups, (meth) acrylates having thiouracil groups, thiiranes Although (meth) acrylate etc. which have group are mentioned, it is not limited to this. These polymerizable monomers containing a sulfur atom in the molecule can be used alone or in combination.

  It is also effective for the present invention to use an organosilane compound having at least one polymerizable unsaturated group in the molecule in order to give the dental adhesive composition of the present invention adhesion to a ceramic or composite resin. is there. Any organosilane compound having a polymerizable unsaturated group in the molecule can be used regardless of the type and number of unsaturated groups and the presence or absence of other functional groups. These organosilane compounds can be used alone or in combination.

  Specific examples of the organosilane compound having a polymerizable unsaturated group that can be used in the dental adhesive composition of the present invention include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyl (β-methoxyethoxy). ) Silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, and the like, but are not limited thereto.

<(C) Filler>
As the filler (c) that can be used in the present invention, known fillers generally used for dental composite materials can be used. (C) Examples of fillers include inorganic fillers, organic fillers, organic-inorganic composite fillers, etc., but these may be used alone or in combination of a plurality of fillers regardless of the type of filler. it can.

  Specific examples of the inorganic filler include silica, aluminum silicate, alumina, titania, zirconia, various glasses (fluorine glass, borosilicate glass, soda glass, barium glass, barium aluminum silica glass, glass containing strontium and zirconium. Glass ceramics, fluoroaluminosilicate glass, synthetic glass by sol-gel method, etc.), Aerosil (registered trademark), calcium fluoride, strontium fluoride, calcium carbonate, kaolin, clay, mica, aluminum sulfate, calcium sulfate, Examples thereof include barium sulfate, titanium oxide, calcium phosphate, hydroxyapatite, calcium hydroxide, strontium hydroxide, and zeolite. These inorganic fillers may be used as aggregates, and examples include silica-zirconia composite oxide aggregates obtained by mixing silica sol and zirconia sol, spray drying and heat treatment.

  Examples of the organic filler include, for example, elastomers such as polyvinyl acetate, polyvinyl alcohol, and styrene-butadiene rubber, monofunctional functions such as polymethyl methacrylate (PMMA), polyethyl methacrylate, polypropyl methacrylate, and polybutyl methacrylate. Non-crosslinkable (meth) acrylate polymer that is a homopolymer of a polymerizable (meth) acrylate polymerizable monomer, polymerization having a monofunctional (meth) acrylate polymerizable monomer and two or more functional groups Examples thereof include, but are not limited to, a crosslinkable (meth) acrylate polymer obtained by copolymerizing a polymerizable monomer, polyvinyl acetate, polyethylene glycol, polypropylene glycol, and polyvinyl alcohol.

Examples of the organic / inorganic composite filler include those in which the surface of the filler is polymerized and coated with a polymerizable monomer, and the filler and the polymerized monomer are mixed and polymerized and then pulverized to an appropriate particle size. Alternatively, those in which a filler is dispersed in advance in a polymerizable monomer and emulsion polymerization or suspension polymerization are exemplified, but the present invention is not limited thereto.
As these fillers, fillers having an arbitrary shape such as a spherical shape, a needle shape, a plate shape, a crushed shape, and a scale shape can be used. The average particle size of the filler varies depending on the type of the filler, and in the case of an inorganic filler, it can be used in the range of 0.01 to 20 μm, preferably 0.01 to 10 μm. It is in the range, more preferably in the range of 0.01 to 5 μm. In the case of an organic-inorganic composite filler, it can be used in the range of 0.05 to 100, preferably 0.5 to 50 μm, more preferably 1 to 30 μm. is there. Further, in the case of organic fillers, there is no particular limitation on the average particle diameter, and any of the average particle diameters in any range can be used. The information on the average particle diameter can be examined with a laser diffraction particle size measuring machine. (C) When the filler is an aggregate, the average particle diameter is the average particle diameter of the aggregate. The average particle diameter of the filler is preferably 0.1 to 20 μm, more preferably 0.1 to 10 μm. In addition, information such as the average particle diameter and the coefficient of variation of the particle diameter can be examined by a laser diffraction particle size measuring machine. (B) When the filler is an aggregate, the average particle diameter is the average of the aggregate. The particle size. If the average particle size is less than 0.1 μm, the dental adhesive composition becomes sticky and air bubbles are easily mixed. When it exceeds 20 μm, the surface smoothness after polishing of the dental adhesive composition is lowered.

  Furthermore, the surface of the filler may be multifunctional by a surface treatment method using a surface treatment agent or the like, and these surface treatment fillers can be used without any limitation. Specific examples of the surface treatment agent used to make the surface of the filler multifunctional include surfactants, fatty acids, organic acids, inorganic acids, various coupling materials (titanate coupling agents, aluminate coupling agents and silanes). Coupling agents), metal alkoxide compounds, and the like. Specific examples of the surface treatment method include a method of spraying a surface treatment agent from the top in a state where the filler is flowed, a method of dispersing the filler in a solution containing the surface treatment agent, and several types on the surface of the filler. The method etc. which carry out multilayer processing of the surface treating agent are mentioned. However, the surface treatment agent and the surface treatment method are not limited to these. These surface treatment agents and surface treatment methods can be used alone or in combination.

  Examples of the silane coupling agent include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, and the like. Preferably γ-methacryloxypropyltrimethoxysilane is used. The surface treatment of the agglomerates and fillers may be performed with the same type of coupling agent or different types of coupling agents.

  Although there is no restriction | limiting in particular in content of (c) filler which can be used for the dental adhesive composition of this invention, (a) Acid group non-containing polymerizable monomer contained in a dental adhesive composition , (B) an acidic group-containing polymerizable monomer, (d) a photopolymerization initiator, and (e) 50 to 900 parts by weight with respect to 100 parts by weight of the total resin component. Is more preferable, and 70 to 800 parts by weight is more preferable. (C) When the filler content is less than 50 parts by weight, sufficient mechanical strength cannot be obtained. In addition, an increase in the content of the (a) non-acidic group-containing polymerizable monomer and (b) the acidic group-containing polymerizable monomer increases the polymerization shrinkage, so that the The possibility of causing problems such as formation of a traction gap increases. On the other hand, when it exceeds 900 parts by weight, it is difficult to obtain a dental adhesive composition in which the filler is uniformly dispersed. Moreover, since content of the (b) acidic group containing polymerizable monomer falls relatively with the increase in content of a filler, the possibility that the self-adhesiveness with respect to a tooth will fall will become high.

<(D) Photopolymerization initiator>
The photopolymerization initiator (d) used in the dental adhesive composition of the present invention is not particularly limited, and any known photopolymerization initiator generally used in the dental field can be used without any limitation.

  As the photopolymerization initiator, a photosensitizer, a photosensitizer / photopolymerization accelerator, and the like can be preferably used. Specific examples of the photosensitizer include benzyl, camphorquinone, α-naphthyl, acetonaphthene, p, p′-dimethoxybenzyl, p, p′-dichlorobenzylacetyl, pentanedione, 1,2-phenanthrenequinone, 1 , 4-phenanthrenequinone, 3,4-phenanthrenequinone, 9,10-phenanthrenequinone, α-diketones such as naphthoquinone, benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, thioxanthone, 2-chlorothioxanthone Thioxanthones such as 2-methylthioxanthone, 2-isopropylthioxanthone, 2-methoxythioxanthone, 2-hydroxythioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, Benzophenones such as zophenone, p-chlorobenzophenone, p-methoxybenzophenone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide Acyl phosphine oxides such as 2-benzyl-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-benzyl-diethylamino-1- (4-morpholinophenyl) -propanone-1, etc. α-aminoacetophenones, benzyl dimethyl ketal, benzyl diethyl ketal, ketals such as benzyl (2-methoxyethyl ketal), bis (cyclopentadienyl) -bis [2,6-difluoro-3- (1-pyrrolyl) Phenyl] -titanium , Such as bis (cyclopentadienyl) -bis (pentanefluorophenyl) -titanium, bis (cyclopentadienyl) -bis (2,3,5,6-tetrafluoro-4-disiloxyphenyl) -titanium And the like.

  Specific examples of the photopolymerization accelerator include N, N-dimethylaniline, N, N-diethylaniline, N, N-di-n-butylaniline, N, N-dibenzylaniline, pN, N- Dimethyl-toluidine, m-N, N-dimethyl-toluidine, p-N, N-diethyl-toluidine, p-bromo-N, N-dimethylaniline, m-chloro-N, N-dimethylaniline, p-dimethylamino Benzaldehyde, p-dimethylaminoacetophenone, p-dimethylaminobenzoic acid, p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid aminoester, N, N-dimethylanthranic acid methyl ester, N, N-dihydroxyethylaniline, p-N, N-dihydroxyethyl- Louisin, p-dimethylaminophenyl alcohol, p-dimethylaminostyrene, N, N-dimethyl-3,5-xylidine, 4-dimethylaminopyridine, N, N-dimethyl-α-naphthylamine, N, N-dimethyl-β -Naphtylamine, tributylamine, tripropylamine, triethylamine, N-methyldiethanolamine, N-ethyldiethanolamine, N, N-dimethylhexylamine, N, N-dimethyldodecylamine, N, N-dimethylstearylamine, N, N- Tertiary amines such as dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, 2,2 ′-(n-butylimino) diethanol, secondary amines such as N-phenylglycine, and 5-butyl barbituric acid 1-benzyl-5-thio Barbituric acids such as enylbarbituric acid, dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dioctyltin diversate, dioctyltin bis (mercaptoacetic acid isooctyl ester) salt, tetramethyl-1,3-diacetoxy distano Examples thereof include tin compounds such as xanthine, aldehyde compounds such as lauryl aldehyde and terephthalaldehyde, and sulfur-containing compounds such as dodecyl mercaptan, 2-mercaptobenzoxazole, 1-decanethiol, and thiosalicylic acid.

Furthermore, in order to improve the photopolymerization promoting ability, in addition to the above photopolymerization accelerator, citric acid, malic acid, tartaric acid, glycolic acid, gluconic acid, α-oxyisobutyric acid, 2-hydroxypropanoic acid, 3-hydroxypropane Addition of oxycarboxylic acids such as acid, 3-hydroxybutanoic acid, 4-hydroxybutanoic acid and dimethylolpropionic acid is effective.
These photopolymerization initiators can be used alone or in combination of two or more. Moreover, there is no problem even if these polymerization initiators are subjected to a secondary treatment such as being encapsulated in microcapsules as necessary.
Furthermore, these various kinds of photopolymerization initiators can be used alone or in combination of two or more kinds irrespective of the polymerization mode and polymerization method.

  (D) Content of photoinitiator is 100 weight of total content of the polymerizable monomer component which consists of (a) acidic group non-containing polymerizable monomer and (b) acidic group containing polymerizable monomer What is necessary is just to select suitably from the range of 0.01-10 weight part by the outer cover with respect to a part. Preferably it is 0.05-7 weight part, More preferably, it is 0.1-5 weight part. (D) When the content of the photopolymerization initiator is less than 0.01 part by weight, the polymerizable monomer cannot be sufficiently polymerized and cured, and high mechanical properties cannot be obtained. On the other hand, when the content exceeds 10 parts by weight, the polymerization curability for the polymerizable monomer is not changed, but a large amount of the polymerization initiator may remain to cause discoloration.

<(E) Chain transfer agent containing α-alkylstyrene compound>
The dental adhesive composition of the present invention comprises (e) a chain transfer agent containing an α-alkylstyrene compound. The effect of the present invention is manifested only when an α-alkylstyrene compound is included among various chain transfer agents. When only other chain transfer agents are used, the polymerization shrinkage stress can be reduced, but at the same time, the polymerization rate, mechanical properties, and adhesion to the tooth tend to decrease, and the performance required as a restoration material. Can not be compatible.

  There is no restriction | limiting in particular as an alpha-alkyl styrene compound, According to the objective, it can select suitably. Specifically, 2-phenyl-1-propene, 2,4-diphenyl-4-methyl-1-pentene, 2,4-diphenyl-4-methyl-2-pentene, 3,5-diphenyl-5- Examples include methyl-2-heptene, 3,5-diphenyl-5-methyl-3-heptene, 1,3-diphenyl-1-butene, and 1,1-diphenylethylene. Preferably, 2,4-diphenyl-4-methyl-1-pentene is used.

  Moreover, as long as the effect of the present invention is not impaired, other chain transfer agents can be used in combination with the α-alkylstyrene compound, and known compounds can be used without any limitation. Specifically, mercaptan compounds such as n-butyl mercaptan and n-octyl mercaptan, terpenoid compounds such as limonene, myrcene, α-terpinene, β-terpinene, γ-terpinene, terpinolene, β-pinene and α-pinene. Etc.

  (E) The addition amount of the chain transfer agent containing an α-alkylstyrene compound is (a) a polymerizable monomer comprising an acidic group-free polymerizable monomer and (b) an acidic group-containing polymerizable monomer. The total content is 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, more preferably 0.1 to 1 part by weight, based on 100 parts by weight. When the addition amount of the chain transfer agent is less than 0.01 parts by weight, there is a possibility that internal strain generated during polymerization of the dental adhesive composition may not be sufficiently suppressed, and sufficient mechanical strength and durable adhesiveness cannot be expressed. . On the other hand, if the amount exceeds 5 parts by weight, the chain transfer agent may inhibit the polymerization and the curability may be lowered, and the residual amount of the unreacted polymerizable monomer in the composition after curing increases. May decrease.

<Other ingredients>
In addition to the above components (a) to (e), the dental adhesive composition of the present invention includes an excipient typified by fumed silica, such as 2-hydroxy-4-methylbenzophenone. Components such as UV absorbers, hydroquinone, hydroquinone monomethyl ether, polymerization inhibitors such as 2,5-ditertiary butyl-4-methylphenol, anti-discoloring agents, antibacterial materials, coloring pigments, and other conventionally known additives are required. It can be arbitrarily added depending on the case.
Furthermore, water and a solvent that can be mixed with water at an arbitrary ratio can be optionally added in consideration of penetrability into teeth, decalcification, and biological safety. Examples of such components include alcohols such as methanol, ethanol and propanol, and ketones such as acetone and methyl ethyl ketone.
The method of using the dental adhesive composition of the present invention is not particularly limited, and is not limited to use alone, but includes other materials such as etching materials, primers, bonding materials, self-etching primers, ceramic primers, metal primers, and precious metal primers. These treatment materials, bonding materials, and filling / restoring materials can be used in appropriate combination. Ingredients such as conventionally known additives can be optionally added as necessary.

Further, before curing of the resin component comprising (a) an acid group-free polymerizable monomer, (b) an acid group-containing polymerizable monomer, (d) a photopolymerization initiator, and (e) a chain transfer agent. It is also an aspect of the present invention that the refractive index na and (c) the refractive index nc of the filler satisfy the relationship of the following formula (1).

| Na-nc | ≦ 0.01 (1)

Thereby, the dental adhesive composition of this invention can obtain high transparency from the positional relationship of the refractive index of (c) a filler and a resin component, and expresses a deep hardening depth.
In this specification, the deep curing depth is defined as a photocuring depth of 3.5 mm or more, more preferably 4.0 mm or more in the measurement of the photocuring depth in accordance with ISO 4049.

  A photopolymerization initiator and a chain transfer agent are also constituents of the resin and affect the refractive index of the resin. However, since the content thereof is small, the influence on the refractive index is considered to be small. However, when the content is large, it affects the refractive index, so it is necessary to adjust the mixing ratio including not only the polymerizable monomer but also the polymerization initiator.

  (C) When a plurality of fillers are used in combination as fillers, (c) Since the refractive index nc of the fillers is additive, the refractive index of each filler is added according to the quantity ratio. Thus, (c) the refractive index nc of the filler can be calculated. However, if the refractive index difference of the filler used is excessively large, even if the above formula (1) is satisfied, the composition becomes turbid and opaque, and the curing depth may be reduced. Therefore, when a plurality of fillers are used in combination, (c) at least 40% by weight, preferably 50% by weight or more, more preferably 60% by weight or more of the filler in 100% by weight of the filler, respectively. It is preferable that the formula (1) is satisfied.

  Moreover, it is also a preferable aspect that the surface of the filler (c) is multifunctionalized by a surface treatment method using a surface treatment agent or the like, and these surface treatment fillers are not limited in any way, and the dental adhesiveness of the present invention. It can be used in a composition. In this case, there is no problem as long as the refractive index nc of the filler (c) satisfies the relationship of Formula 1 based on the refractive index before multifunctionalization in each surface treatment method.

In the dental field, various color systems are used to measure and digitize the color tone of dental materials such as tooth, artificial teeth, porcelain, and hard resin, while opacity in dental filling materials is used. There is a contrast ratio using the Y value related to the brightness among the tristimulus values in the XYZ color system defined in JIS Z8701.
Place a disc-shaped test specimen with a certain thickness on a standard white background or standard black background, and illuminate it under certain conditions (light source, irradiation area, etc.), brightness of white background (Yw) and black The brightness (Yb) of the background is measured, and the contrast ratio is calculated from a specific formula. Since the contrast ratio is affected by the thickness of the specimen, the dental material and instrument Vol. The contrast ratio of the dental adhesive composition of the present invention is calculated using the formula (2) described in 14 Special Issue 26 (1995).

Contrast ratio = 1- (1-Yw / Yb) ^ (1 / L) (2)

The closer the value of the contrast ratio is to 1, the more opaque the material is, and the closer to 0 the more transparent the material.
The dental adhesive composition of the present invention comprises (a) an acid group-free polymerizable monomer, (b) an acid group-containing polymerizable monomer, (d) a photopolymerization initiator, and (e) a chain transfer. When the refractive index na before curing of the resin component made of the agent and the refractive index nc of the filler (c) satisfy the relationship of the above formula (1), the contrast ratio value before curing is 0.5 or less. More preferably, it becomes 0.4 or less.
When the contrast ratio before curing of the dental adhesive composition of the present invention exceeds 0.5, the transparency of the dental adhesive composition is too low, and the photocuring depth may be lowered. Moreover, there is a concern that the polymerization rate of the dental adhesive composition of the present invention is also lowered and the adhesiveness is lowered.

Further, the dental adhesive composition of the present invention comprises (a) an acidic group-free polymerizable monomer, (b) an acidic group-containing polymerizable monomer, (d) a photopolymerization initiator, and (e). When the refractive index na before curing of the resin component comprising the chain transfer agent and the refractive index nc of the filler (c) satisfy the relationship of the above formula (1), the refractive index of the resin increases after curing. (C) The difference from the refractive index nc of the filler is increased. As a result, the composition becomes opaque after curing, and the contrast ratio value after curing is in the range of 0.4 to 0.8, and the background color such as the cavity wall can be shielded by being appropriately opaque. Excellent aesthetics can be obtained without being affected by the background color.
When the contrast ratio after curing of the dental adhesive composition of the present invention exceeds 0.8, the transparency is too low, which may impair aesthetics. On the other hand, when the contrast ratio after curing is less than 0.4, the transparency of the dental adhesive composition is too high, so the background color of the cavity wall or the like cannot be blocked, and the influence of the background color Cause aesthetics to be impaired.

  EXAMPLES Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

  The test methods employed in the examples and comparative examples are as follows.

(1) Refractive Index Measurement of Filler Several types of refractive index measurement immersion liquids having an arbitrary refractive index are prepared in advance using tricresyl phosphate and dioctyl adipate (both manufactured by Daihachi Chemical Industry). In a constant temperature room at 25 ° C., a small amount of filler is collected on a slide glass, a few drops of the prepared immersion liquid are dropped and mixed uniformly, and then a cover glass is placed on to make a measurement sample. The refractive index of the immersion liquid when the measurement sample became the most transparent was measured and used as the refractive index of the filler.
(2) Refractive index measurement of polymerizable monomer The refractive index (25 ° C.) of the resin component prepared using an Abbe refractometer (manufactured by Atago Co., Ltd .: 2T type) was measured.

(3) Opacity measurement After the prepared dental adhesive composition was filled in a stainless steel mold (15φ × 1 mm: disk shape), a cover glass was placed from above and pressed using a glass plate. With the cover glass attached, the test specimen was either a standard white plate (D65 / 10 ° X = 81.07, Y = 86.15, Z = 93.38) or a standard black plate (D65 / 10 ° X = 0.0, Y = 0.0, Z = 0.0) respectively, and using a color guide spectral colorimeter (manufactured by Big Chemie), under predetermined constant conditions (light source: C, viewing angle: 2 °, measurement area) : 11 mm), and the brightness (Yw) of the white background before curing and the brightness (Yb) of the black background were measured.
After that, the photopolymerization irradiator (Griplight II: made by Matsukaze) was used for light curing for 1 minute from the cover glass, the cured product was taken out from the mold, and the specimen was cured according to the above procedure. The brightness of the subsequent white background (Yw) and the brightness of the black background (Yb) were measured. The thickness of the test specimen was measured using a micrometer at five points, and the average value was taken as the specimen thickness. The contrast ratio (C) before and after curing of the dental adhesive composition was calculated from the formula (2) from the measured values of Yw, Yb and the thickness of the specimen before and after curing thus obtained.

(4) Tooth adhesion test After extracting the frozen central incisors of the extracted bovine mandibular jaws within 24 hours, thaw, then remove the root and cut the crown to prepare bovine tooth fragments. Then, the bovine tooth pieces are embedded with epoxy resin. Under water injection, the embedded bovine teeth are exposed to enamel or dentin using # 600 water-resistant abrasive paper, washed and dried.
A double-sided tape with a hole with a diameter of 4 mm is attached to the exposed enamel or dentin to define the adhesive surface. A plastic mold (inner diameter: 4 mm, height: 2 mm or 4 mm) is fixed to the specified surface, the adhesive surface is filled with a dental adhesive composition, and 20 seconds using a photopolymerization irradiator (Griplight II: Matsukaze) Cure by light irradiation. Thereafter, the mold was removed to prepare an adhesion test body. After this adhesion test specimen was immersed in distilled water at 37 ° C. for 24 hours, using an Instron universal testing machine (Instron 5567, manufactured by Instron), tooth adhesion by shearing adhesive strength at a crosshead speed of 1 mm / min. A test was conducted to measure the initial bond strength.
In addition, an adhesion test body was prepared and immersed in distilled water at 37 ° C. for 24 hours, and then subjected to a thermal cycle of 2,000 times, and the result of the tooth adhesion test was defined as the durable adhesion strength.

(5) Bending strength After filling the prepared dental adhesive composition in a stainless steel mold, place cover glasses on both sides and press-contact with a glass plate, then use a photopolymerization irradiator (Blue Shot: Matsukaze) It was cured by irradiation with light at 5 locations for 10 seconds. After curing, the cured product was taken out from the mold, and the back surface was similarly irradiated with light again to obtain a test body (25 × 2 × 2 mm: rectangular parallelepiped type). The test specimen was immersed in water at 37 ° C. for 24 hours, and then subjected to a bending test.
The bending test was performed using an Instron universal testing machine (Instron 5567, manufactured by Instron) at a fulcrum distance of 20 mm and a crosshead speed of 1 mm / min.
The test was conducted with 10 specimens, and the average value was evaluated.
(6) Polymerization shrinkage stress After applying a metal primer on an iron plate (material SPCC, inner diameter 10 mm, thickness 1 mm) with a strain gauge (Kyowa Denko, KFG-2-120-C1-11) attached, a fluororesin ring It was placed in a metal mold (inner diameter: 10 mm, thickness: 2 mm), and the dental adhesive composition was filled in a thickness of 1 mm on the primer application surface. Light irradiation was performed from above, the distortion of the iron plate due to curing was measured, and the polymerization shrinkage stress was calculated by multiplying the strain value after 600 seconds of light irradiation and 24 hours after the light irradiation by the elastic modulus of the iron plate based on the following formula (3). .

Polymerization shrinkage stress (MPa) = ε x E Formula (3)
ε: Strain
E: Elastic modulus

(7) Polymerization rate The infrared absorption spectrum of the prepared dental adhesive composition was measured by the KBR method of an infrared absorption spectrometer (JASCO FT-IR-6300, manufactured by JASCO Corporation) (measurement range: 400 to 4000 cm). -1). The peak height (h) attributed to the (meth) acrylate double bond (1637 cm-1) and the carbonyl group (1717 cm-1) of the dental adhesive composition before curing was measured. The relative unpolymerized monomer amount of each material was determined by the ratio (Ib) of the peak height before curing of the double bond (1637 cm-1) / carbonyl group (1717 cm-1). Thereafter, the dental adhesive composition was cured by irradiating with light for 10 seconds using a photopolymerization irradiator (Blue Shot: manufactured by Matsukaze). The peak height (h) attributed to the (meth) acrylate double bond (1637 cm-1) and the carbonyl group (1717 cm-1) was measured immediately after irradiation and after 24 hours according to the above procedure, and the peak height after curing. The ratio (Ia) was determined. From the ratio of the peak height before and after the obtained curing, the polymerization rate (%) immediately after light irradiation and after 24 hours was calculated from the following formula (4).

Polymerization rate (%) = 100−Ia / Ib x 100 (4)

(8) Depth of light curing The prepared dental adhesive composition was filled in a stainless steel mold having a diameter of 4 mm × 12 mm, cover glasses were placed on both sides and pressed with a glass plate, and then a photopolymerization irradiator (Blue Shot: (Made by Matsukaze) was irradiated with light for 10 seconds each and cured. After curing, the cured product is taken out from the mold, the unpolymerized paste is removed with a plastic spatula, the thickness of the cured product is measured with a micrometer, and a value obtained by halving it is defined as the photocuring depth (mm). .

The materials used in Examples and Comparative Examples and their abbreviations are shown below.
[Acidic group-free polymerizable monomer (a)]
Bis-GMA: 2,2-bis [4- (3-methacryloyloxy-2-hydroxypropoxy) phenyl] propane (refractive index before curing: 1.552)
UDMA: N, N- (2,2,4-trimethylhexamethylene) bis [2- (aminocarboxy) ethanol] methacrylate (refractive index before curing: 1.383)
3G: Triethylene glycol dimethacrylate (refractive index before curing: 1.460)

[Acid group-containing polymerizable monomer (b)]
6-MHPA: (6-Methacryloxy) hexylphosphonoacetate (refractive index before curing: 1.473)
10-MDP: 10-methacryloyloxydecyl dihydrogen phosphate (refractive index before curing: 1.468)

[Hydrophilic polymerizable monomer containing no acidic group (f)]
-HEMA: 2-hydroxyethyl methacrylate (refractive index before curing: 1.451)
701A: 2-hydroxy-3-acryloyloxypropyl methacrylate (refractive index before curing: 1.471)

[Filler (c)]
The refractive index and average particle diameter of the inorganic particles 1 to 3 of the filler used for the preparation of the dental adhesive composition were measured, and the results are shown in Table 1. These inorganic particles were appropriately silane treated and used for the preparation of a dental adhesive composition.

[Polymerization initiator (d)]
CQ: α-camphorquinone DMABE: ethyl N, N-dimethylaminobenzoate

[Chain transfer agent (e)]
Α-MSD: 2,4-diphenyl-4-methyl-1-pentene DMH: 3,5-diphenyl-5-methyl-2-heptene γ terpinene TEMPO: 2,2,6,6-tetramethyl Piperidine 1-oxyl free radical

[Preparation of resin components (I1 to I21)]
Resin components (I1 to I21) were prepared with the compositions shown in Table 2, respectively.

(Preparation of dental self-adhesive restorative material)
Using the resin components shown in Table 2, dental self-adhesive restorative materials (Examples 1 to 17 and Comparative Examples 1 to 6) were prepared according to the composition of Table 3.

The suitability for Formula 1 was evaluated from the relationship between the refractive index of the filler and the resin component contained in the dental self-adhesive restorative materials (Examples 1-17 and Comparative Examples 1-6). The results are shown in Table 4.
| Na-nc | ≦ 0.01 (1)

Tables 5 and 6 show the evaluation results of the dental self-adhesive restorative materials of Examples 1 to 17 and Comparative Examples 1 to 6.

[Examples 1 to 17]
The dental self-adhesive restorative materials of Examples 1 to 17 showed an increase in the polymerization rate after 24 hours although the polymerization rate was low immediately after light irradiation. Further, the polymerization shrinkage stress is low both after 600 seconds and 24 hours, and the bending strength is also high. That is, by containing an α-alkylstyrene compound as a chain transfer agent, it is possible to effectively delay the gelation point at the initial stage of polymerization without hindering the final polymerization rate, resulting in low polymerization. It can be seen that both shrinkage stress and good bending strength are achieved. Furthermore, the durable adhesive strength with respect to dentine and enamel is also a high value, and it was recognized that it has the self-adhesion property to the stable dentine.
Furthermore, the dental self-adhesive restorative materials of Examples 1 to 5, 8 to 12, and 14 to 17 that conform to the formula (1) and have high transparency before curing have a photocuring depth of 4 mm or more. It was confirmed that the adhesion strength to dentin and enamel did not decrease even in the case of 4 mm.

[Comparative Example 1]
Since the dental self-adhesive restorative material of Comparative Example 1 did not contain a chain transfer agent, it was confirmed that the polymerization rate immediately after light irradiation was high and the polymerization shrinkage stress was also high. Further, regarding the adhesive strength to dentin and enamel, although it had adhesiveness in the initial stage, in the durability adhesion test, the specimen was dropped and the adhesiveness was reduced.

[Comparative Example 2]
The dental self-adhesive restorative material of Comparative Example 2 contains an α-alkylstyrene compound as a chain transfer agent but does not contain an acidic group-containing polymerizable monomer. Does not have adhesiveness to quality.

[Comparative Examples 3 to 6]
The dental self-adhesive restorative materials of Comparative Examples 3 to 6 contain a chain transfer agent other than the α-alkylstyrene compound and have a low effect of suppressing the polymerization rate immediately after light irradiation. When the γ-terpinenes of Comparative Examples 3 and 4 were used, the polymerization shrinkage stress decreased after 600 seconds of light irradiation, but increased after 24 hours, and the bending strength tended to decrease. Further, the dental self-adhesive restorative materials of Comparative Examples 3 to 6 have significantly low adhesion strength to dentin and enamel, and it was observed that the specimens frequently dropped in the durability adhesion test.
In the above description, a single-paste dental self-adhesive restorative material has been described, but the present invention is naturally applicable to a dental adhesive composition in which two or more pastes or liquids are mixed.

According to the present invention, it has mechanical properties and aesthetics required for a restoration material, and has excellent durable adhesive strength to a tooth, and is hardly affected by polymerization shrinkage stress even when it is filled and cured in a lump. It is possible to provide a one-paste dental adhesive composition that exhibits excellent durable adhesiveness.

Claims (6)

(A) an acidic group-free polymerizable monomer,
(B) an acidic group-containing polymerizable monomer,
(C) filler,
(D) a photopolymerization initiator,
(E) a chain transfer agent,
A dental adhesive composition comprising
(E) The dental adhesive composition, wherein the chain transfer agent comprises an α-alkylstyrene compound. (A) an acidic group-containing polymerizable monomer and (b) an acidic group-containing polymerizable monomer, (a) an acidic group-free polymerizable monomer: (b) an acidic group-containing polymerizable monomer The dental adhesive composition according to claim 1, comprising a weight ratio of 99: 1 to 70:30. For 100 parts by weight of the polymerizable monomer component consisting of (a) an acidic group-free polymerizable monomer and (b) an acidic group-containing polymerizable monomer,
(D) Photopolymerization initiator: 0.01 to 10 parts by weight (e) Chain transfer agent: 0.01 to 5 parts by weight, and
For 100 parts by weight of a resin component comprising (a) an acid group-free polymerizable monomer, (b) an acid group-containing polymerizable monomer, (d) a photopolymerization initiator, and (e) a chain transfer agent.
(C) Filler: The dental adhesive composition according to claim 2, comprising 50 to 900 parts by weight. The (a) acidic group non-containing polymerizable monomer contains 100 parts by weight of the acidic group-free hydrophilic polymerizable monomer in an amount of (f) 5 to 70 parts by weight. Dental adhesive composition. The dental adhesive composition according to any one of claims 1 to 4, wherein (e) the chain transfer agent is 2,4-diphenyl-4-methyl-1-pentene. Refractive index na before curing of a resin component comprising (a) an acid group-free polymerizable monomer, (b) an acid group-containing polymerizable monomer, (d) a photopolymerization initiator, and (e) a chain transfer agent. The dental adhesive composition according to claim 1, wherein (c) the refractive index nc of the filler satisfies the relationship of the following formula (1).